package com.dpf.api.utills;

import java.security.MessageDigest;

/**
 * md5加密
 */
public class Md5Util {
    private static final String[] HEX_DIGITS = {"0", "1", "2", "3", "4",
            "5", "6", "7", "8", "9", "A", "B", "C", "D", "E", "F"};

    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0) {
            n += 256;
        }
        int d1 = n / 16;
        int d2 = n % 16;
        return HEX_DIGITS[d1] + HEX_DIGITS[d2];
    }

    private static String byteArrayToHexString(byte[] b) {
        StringBuffer resultSb = new StringBuffer();
        for (int i = 0; i < b.length; i++) {
            resultSb.append(byteToHexString(b[i]));
        }
        return resultSb.toString();
    }

    /**
     * 加密方法
     *
     * @param origin      入参数
     * @param charsetname 编码
     * @return 密文
     */
    public static String md5Encode(String origin, String charsetname) {
        String resultString = null;
        try {
            resultString = origin;
            MessageDigest md = MessageDigest.getInstance("MD5");
            if (charsetname == null || "".equals(charsetname)) {
                resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
            } else {
                resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetname)));
            }
        } catch (Exception exception) {
            exception.printStackTrace();
        }
        return StringUtils.isEmpty(resultString) ? resultString : resultString.toLowerCase();
    }

    /**
     * 加密方法
     *
     * @param origin 入参数
     * @return 密文
     */
    public static String md5Encode(String origin) {
        return md5Encode(origin, "utf-8").toLowerCase();
    }

    public static void main(String[] args) {
        System.out.println(md5Encode("SK"));
    }
}